In this work, we study the nature of long-lived photoexcitations in intercalated, partially and
predominantly non-intercalated semicrystalline poly(2,5-bis(3-tetradecyl-thiophen-2-yl)thieno
[3,2,-b]thiophene) (pBTTT):phenyl-C61 -butyric acid methyl ester (PC61BM) blend films by
quasi-steady-state photoinduced absorption (PIA) spectroscopy. We find that polarons are generated in
these microstructures. However, the polarons generated in partially and predominantly non-intercalated
films (1.7 eV) are at higher energy than in intercalated film (1.4 eV). After comparing with the polaron
generation in neat pBTTT polymer film, we propose that the polarons generated in partially and
predominantly non-intercalated film are delocalized charges, and the polarons generated in intercalated
film are localized charges. Furthermore, we also find that the polarons generated in the partially
non-intercalated film have the longest lifetime.